TY  - JOUR
AU  - Mowe, Patrick
AU  - Pfeiffer, Felix
AU  - Maus, Oliver
AU  - Zeier, Wolfgang
AU  - Winter, Martin
AU  - Neuhaus, Kerstin
TI  - Relationship between structure and room-temperature charge transport in highly acceptor-doped ceria and zirconia
JO  - Solid state ionics
VL  - 428
SN  - 0167-2738
CY  - Amsterdam [u.a.]
PB  - Elsevier Science
M1  - FZJ-2025-03028
SP  - 116955
PY  - 2025
AB  - Even though mainly known for intermediate to high temperature applications, highly acceptor doped ceria and zirconia are potential candidates for use as proton conductive membranes or for electro-chemo-X devices, which requires comparably high ionic conductivity at room temperature. In this study, the composition La2Ce2O7, Y2Zr2O7 and La2Zr2O7 were prepared via Pechini synthesis, followed by calcination, pellet pressing and sintering. The received pellets were characterized by X-ray diffraction (XRD), X-ray pair distribution function analyses (XPDF), and Raman spectroscopy showing La2Zr2O7 as a pyrochlore, a global fluorite structure in Y2Zr2O7 and La2Ce2O7 as defective pyrochlore structure with local disorder. The investigation of electrical properties using classical electrochemical methods, such as electrochemical impedance spectroscopy (EIS), is constrained by very low electrical conductivity at room temperature for the investigated ceramics. To enable measurements at room temperature, and with a focus on the surface-near transport properties, a combination of Kelvin Probe Force Microscopy (KPFM) and local polarization-relaxation measurements has been employed in this study. The application of KPFM-based polarization-relaxation measurements enabled the successful determination of diffusion coefficients in both dry and wet environments by employing positive or negative polarization voltages with highest values for the defective pyrochlore La2Ce2O7. Additionally, KPFM measurements were used to analyze the local potential distribution at the grain boundaries. The results are discussed in the context of a defect model.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:001534877700001
DO  - DOI:10.1016/j.ssi.2025.116955
UR  - https://juser.fz-juelich.de/record/1044112
ER  -